<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>栅格系统响应式工具</title>
    <link rel="stylesheet" href="./bootstrap/css/bootstrap.min.css">
    <style>
        .row div{
            background-color:purple;
            height: 300px;
        }

        .row div:nth-child(3){
            background-color: pink;
        }

        span{
            font-size: 50px;
            color: #fff;
        }
    </style>
</head>
<body>
    <div class="container">
        <div class="row">
            <div class="col-xs-3">
                <!-- visible-lg:只有大屏幕才显示 -->
                <span class="visible-lg">我会显示哦</span>
            </div>
            <div class="col-xs-3">2</div>
            <div class="col-xs-3 hidden-md hidden-xs">我会变魔术哦</div>
            <div class="col-xs-3">4</div>
        </div>
    </div>
</body>
</html>